Question

An instructor of a biology class believes the average final exam score for his biology class was more than 75.

Suppose a sample of 25 was taken and the sample mean he observed was 78.48 and a standard deviation of 5 points. What is the value of the test statistic? Report your answer to 2 decimal places.

(hint: to determine which test statistic to calculate, you must think about what methods should be used. Either one-sample t-methods, one-sample z-methods or two-sample t-methods.

Answer 1

Solution :

= 75

=78.48

s =  5

n = 25

This is the right tailed test .

The null and alternative hypothesis is ,

H₀ :    = 75

H_a : > 75

Test statistic = t

= ( - ) / s / n

= (78.48 - 75 ) /  5 / 25

= 3.480

Test statistic = t = 3.480